uls-tracker
Sign in
Confidence: Medium · Source: FCC ULS · As of 2026-09-12

K6BAU callsign genealogy

Currently held by Bau, William D

The FCC publishes a previous_call_sign on every amateur license — a self-link to the licensee's prior callsign. Following those links produces the chain below.

Previous callsigns

Older callsigns held by K6BAU's current licensee, walking backwards.

  1. KM7AJOcancelled· G
    Bau, William DNVgranted 2025-04-24cancelled 2025-05-23

Successor callsigns

Callsigns held now by people who previously held K6BAU.

No current licensee on record previously held this callsign.

All historical holders

Every license row we've seen with the callsign K6BAU, oldest first.

  • CASILLAS, WILLIAM A CA
    1987-09-08 → cancelled 1999-09-10
  • Bau, William D CA
    2011-07-12 → cancelled 2023-07-13
  • Bau, William D NV
    2025-05-23 active